Slide fasteners



April 11, 1961 H. ERDMANN 2,978,773

SLIDE FASTENERS Filed Aug. 26, 1958 2 Sheets-Sheet 1 FIG. 2

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ATTORNEY April 11, 1961 H. ERDMANN SLIDE FASTENERS Filed Aug. 26, 1958 2 Sheets-Sheet 2 ATTORNEY w m w m HANS ERDMA Unitfid States atent SLIDE FASTENERS Hans Erdmann, Maplewood, N.J., assignor to Waldes Kohinoor, Inc., Long Island City, N.Y., a corporation of New York Filed Aug. 26, 1958, Ser. No. 757,272

7 Claims. (Cl. 24-20514) This invention relates to improvements in slide fasteners, and more particularly to an improved pull tab for the so-called cam-lock slider employed to open and close such a slider and which is adapted to frictionally lock with one or more of the fastener elements of the fastener chain moving through the slide channel when its pull tab occupies its normal lowered position in which it lies flat against the front Wing of the slider.

As is now well known in the slide fastener art, there are three main classes or types of lock sliders for slide fasteners, namely, the pin-lock slider whose pull tab carries a depending locking pin which in the normal lowered position of the pull tab projects through an opening in the front slider wing into the space between two adjacent fastener elements of the fastener chain then within the slider channel, thereby preventing further movement of the slider along the fastener chain; the automatic lock slider whose pin-like locking member is normally biased by spring means to a locking position within the slider channel, said means yielding when the pull tab is manually raised to actuate the slider in fastener-opening direction; and the cam-lock slider whose pull tab carries a depending cam or lug which in the normal lowered position of the pull tab presses down on the one fastener element (or on the two staggered elements of the fastener chain) disposed below same with sufficient force as to fiictionally lock the slider to the chain.

The present invention is concerned with improvements in sliders of the aforesaid third class, i.e. the cam-lock slider, and more particularly in such a slider whose locking cam or lug is formed by bending a finger-like extension (or two such extensions if two locking cams are desired), which initially projects from the upper end of the pull tab and lies within the plane thereof, back under the pull tab so that it depends therefrom while lying in a plane which is spaced an appreciable albeit small distance from that of the pull tab proper. While functioning satisfactorily as a cam lock, such a cam is open to the objection that it is likely to become distorted and even broken from its pull tab under pressure such as is exerted thereon when ironing the garment for which the slider fastener provides a placket or opening closure, and when such happens the slider is unable to cam-lock to its fastener as intended. Moreover, previous attempts to overcome this objection were not entirely satisfactory.

A main object of this invention, therefore, is to provide a cam-lock slider as aforesaid with effective and reliable means for strengthening the cam of the pull tab against distortion under the various forces to which the slider, and more especially the pull tab, are subjected in normal use.

A more particular object of the invention is to devise such a means which, in addition to insuring superior functioning of the slider for its life time, may be simply and economically applied to sliders during normal manufacture.

Yet a more specific object of the invention is to provide a pull tab for a so-called cam-lock slider for slide fasteners whose construction and arrangement is such as to give protection and reinforcement to the cam formed on the'pull tab by bending a finger-like extension thereof back under the pull-tab proper so as to lie parallel there with, against forces tending to distort and/or flatten the cam against the under side of said pull tab as would irnpair the functioning thereof as a cam lock.

The above and other objects and features of advantage of the improved pull tab for camlo-ck sliders according to the invention will appear from the following detailed description thereof, wherein reference is had to the accompanying drawing illustrating a standard cam-lock slider incorporating one form of improved pull tab and various forms which said pull tab may take, wherein:

Fig. l is a plan view of a cam lock slider employing the improved pull tab featuring the present invention;

Fig. 2 is a longitudinal section taken through Fig. 1 on line 22 thereof;

Figs. 3, 5 and 7 are broken-away plan views illustrating variant forms which the improved slider pull-tab for a cam-lock slider shown in Figs. 1 and 2 may take, the views looking on to the under side of the pull tab; and

Figs. 4, 6 and 8 are sectional views taken on lines 4-4, 66 and 8-8 of Figs. 3, 5 and 7, respectively.

Referring to the drawings, Figs. 1 and 2 illustrate one form of improved pull tab according to the invention applied to a conventional cam-lock slider comprising Y- shaped front and rear wings 10, 12 which are connected in spaced, parallel relation at the mid points of their respective top edge-s by a neck 14 which also serves as a divider for separating the interengaged, oppositely disposed fastener elements designated 16a-16c of a slide fastener chain contained within the slider channel, when actuated thereagainst. It will be understood that when the slider is moved in fastener-opening direction, the neck or divider 14 separates the oppositely disposed, coupled fastener elements of the chain, thereby to open the fastener, and when moved in the opposite direction, the slide acts progressively to draw together and interengage, LE. couple, said oppositely disposed fastener elements, thereby to close the fastener.

Associated with the slider body and serving as a convenient means for actuating the slider in either fasteneropening or fastener-closing direction as desired is a pull tab 18 which is pivotally connected at its upper end to the slider body as by means of trunnions 20a, 2012 which extend towards one another and project into the eye of a bail 22 preferably struck from the material of the slider front wing ill. The aforesaid pivotal connection between the pull tab 18 and the slider body provides for movement of the pull tab from its normal lowered position in which it lies close against the slider body to a raised position in which it may be readily grasped when movement of the slider along the fastener is desired. Integral with the pull tab and depending inwardly there from is at least one locking cam or lug 24 which, when the pull tab is in its normal lowered position as a'fo're said, projects through a window 'or opening 26 in the slider front wing into the slider channel. Thus, the lug 24 is adapted to press down on and frictionally lock against the upper surface of at least one, or more often two, of the fastener elements of the same fastener stringer then contained within the slider channel, 'illustratively the two adjacent elements 16a, 16b of the same fastener stringer. Usually, the locking cam or lug 24 also presses the fastener element or elements engaged thereby into a holding pocket therefor formed in the inner face or the rear wing 12 of the slider, such a pocket being generally indicated at 23 in Fig. 2. In the event two lock= ing lugs 24 are provided, such are disposed symmetrically to the longitudinal center line of the pull tab 18 anda-re moreover spaced from one another laterally a distance 3 corresponding to the spacing between the two rows of fastener elements of the companion stringers which constitute the fastener chain. Regardless of whether one or twolocking lugs 24 areemployed, each has lateral position enabling it to line up with the fastener elements of the same fastener stringer and preferably also it has longitudinal dimension suflicient to bridge two adjacent fastener elements of the same fastener stringer.

Usually, a cam-locking lug as aforesaid is formed on the pull tab 18 by initially providing it with an upper edge,'finger-like extension and thereupon bending said extension back under the pull tab so that it extends in spaced parallel relation thereto, the spacing being necessary to provide the lug with the requisite depth enabling it to project through the front wing window 26 and into pressure engagement with the top surfaces of one or more of the fastener elements within the slider channel, aspreviously explained. While functioning satisfactorily asa so-called cam lock, such a cam or lug is open to the objection that it is liable to become distorted or flattened against the pull tab under pressure such as is exerted thereon when ironing the garment to which the fastener is applied. When such occurs, the cam-locking function of the slider is impaired, if not lost completely.

According to the invention, this disadvantage of a cam-lock slider whose cam-locking lug is formed as aforesaid is overcome by the provision of special support means effective between the pull tab and the locking lug which represents the latter from being distorted or flattened against the pull tab in use of the fastener. More particularly, the cam-locking lug is buttressed and reinforced against distortion'toward the pull tab 18 by means of an embossment formed on the under side of the latter which reaches towards and substantially engages with the cam-locking lug, thus in eifect bridging the space between pull tab and lug. Such an embossment (designated 30 in Figs. 1-4) may have the form of a short-width transverse rib whose width corresponds to that of the cam lug which it supports and reinforces; or it may have circular configuration as characterizes the embossment 32 of the Figs. 5 and 6 modification; or it may have wide rib-like configuration as characterizes the embossment 34 of the Figs. 7 and 8 modification, wherein it will be observed that the rib extends substantially the full width of the pull tab, except throughout its area that is cut away to accommodate the bail 22 of the slider. Since the illustrated pull tab is provided with two cam-locking lugs,

one for each of the two rows of fastener elements of the conventional fastener chain, the pull tab in such case is provided with two embossments for supporting and reinforcing same as explained above.

While the aforesaid embossments 3t), 32, 34 may be formed in various ways, it is preferred that they be formed on the pull tab simply by sinking a depression 36 in the front face thereof as results in displacement of the metal towards the opposite or inner face and the formation on said latter face of the desired embossment. In other words, the embossments, regardless of their particular configuration, may be said to be struck from the material of the pull tab itself and thus may be simply formed on the pull tab during the course of its normal manufacture.

Without further analysis, it will be appreciated that the invention overcomes an undesirable aspect of the prior cam-lock sliders, i.e. that its cam-locking lug was liable'to distortion in use, through the provision of an improved pull tab for such a slider whose construction is such that it provides support and reinforcement for the cam-locking lug suificient to positively prevent any such unwanted distortion thereof. It will also be observed that the cam-lock strengthening and reinforcing means provided by the present invention, in addition to being effective and dependable, is also featured by the fact that it may be simply applied to the pull tab during normal'manufacture thereof and without the requirement for complicated dies or other special fabricating ma- I chinery. I

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description orshown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. e

V Iclairn;

l. In a cam-lock slider fora slide fastener comprising a slider body constituted by spaced front and rear wings connected at one end by a neck defining with'said wings a Y-shaped slider channel for movement of the fastener chain therethrough, a pull tab pivotally connected to the front wing having raised and lowered positions with respect thereto and when raised providing pull means for actuating the slider body along the fastener in fastener opening and closing directions, and a locking.

cam on the pull tab adapted in the lowered position of the pull tab to project through an opening in the front wing into frictional engagement with at least one fastener element of the fastener chain then contained within the channel, said cam comprising a fingerlike extension on the top end of the pull tab said pull tab and extension being of substantially the same uniform thickness and said extension underlying the pull tab proper and being disposed in spaced, generally parallel relation therewith, the improvement comprising an embossment on and protruding from the under side of the pull tab into substantial engagement with the cam, said embossment reinforcing the cam against forces tending to distort and/or crush the cam against the pull tab.

2. The improvement in a slide fastener substantially as set forth in claim 1, wherein said embossment has riblike configuration and extends the width of the'cam. I

3. The improvement in a slide fastener substantially as set forth in claim 1, wherein said embossment has circular configuration.

4. The improvement in a slide fastener substantially as set forth in claim 1, wherein said embossment has riblike configuration and extends the full width of the pull tab.

5. A cam-lock slider for a slide fastener comprising a slider body having front and rear wings, a neck connecting said wings in spaced parallel relation and cooperating therewith to define a Y-shaped channel extending through the slider body, a pull tab pivotally connected to the front wing for movement from and to raised and lowered positions with respect thereto and, when raised, providing pull means for actuating the slider body along the fastener in fastener opening and closing directions, and a locking cam on the pull tab adapted in the lowered position thereof to project through an opening in the front wing into frictional engagement with at least one fastener element of the fastener chain then contained within the slider channel, said pull tab and cam having substantially the same uniform thickness and said cam comprising an integral finger-like extension on the top end of the pull tab underlying the pull tab proper and being disposed in spaced, generally parallel relation therewith, said pull tab having an embossment protruding from its under side into engagement with the cam and reinforcing said cam against forces tending to distort or flatten the same against the pull tab.

6. A cam-lock slider for a slide fastener substantially as set forth in claim 5, wherein said embossment has riblike configuration in plan.

7. A cam-lock slider for a slide fastener substantially as set forth in claim 5, wherein the embossment has circular configuration.

References Cited in the file of this patent UNITED STATES PATENTS 1,991,831 Winterhalter Feb. 19, 1935 2,865,075 Firing Dec. as. 1958 

